There is a grommet also called a pin grommet and the like comprising the axis body and the main body wherein the axis body is pushed in. (See Patent Document 1) Such a grommet has a structure such that from a state wherein a leg portion of the main body is inserted and passed through a through-hole formed in a fastening object, the axis body is pushed into the main body so as to spread such leg portion, and fastened to such a fastening object. In the grommet described in the Patent Document 1, in an end of the axis body, there is formed a concave portion which constricts the axis body. In a state wherein the axis body has not been completely pushed into the main body, a claw portion formed inside an end of the leg portion of the main body enters into the concave portion, and the main body and the axis body are temporarily attached. However, in the grommet described in the Patent Document 1, even when the main body and the axis body are temporarily attached in such a manner, the axis body is required to be pushed into the main body while elastically deforming the leg portion of the main body up to a position wherein the aforementioned claw portion is entered into the concave portion.